Strategy for applying a digital SF6 monitoring device to high voltage circuit breakers

This paper describes the strategy for implementing SF6 monitoring devices that were developed to integrate electronic systems for diagnostic and monitoring of the SF6 function of circuit breakers. The advancement of processes controlled by microprocessors and their improved reliability, in conjunction with the high competitiveness of North American utilities due to deregulation, means that high reliability monitoring of SF6 is seen as to decrease safely the scheduled maintenance expenditures of which SF6 maintenance is a large part. It also replies to today's environmental concerns about greenhouse gases. These diagnostic and monitoring systems are tailored to the very diversified demands of each utility and are seen by many as a technological answer to the passage from high "scheduled maintenance" cost due to unreliable SF6 monitoring to "an optimized maintenance" or, in other words, to only on-demand maintenance. The main objective is to increase the availability, and ultimately, the overall reliability of the transmission system by optimization of the maintenance practice, to make the utility more cost competitive within the total life cost of a high voltage circuit breaker by less regular maintenance, in a "New World" of electrical power deregulation.